Differential stage lift flow device



y 15, 1941- A. BOYNTON 2,248,951

DIFFERENTIAL STAGE LIFT FLOW DEVICE Filed Dec. 8, '1939 A TTOR/VEYS.

Patented July 15, 1941 Application December 8, 1939, Serial No. 308,310Claims. (01. 137-111) My invention relates to flowing devices for wells'and broadly includes the subject matter of my copending application,Serial Number 308,308, flled December 8, 1939.

The principal object is tostart wells at relatively low pressures and toflow them at low pressures with resulting low gas-oil ratios.

In accomplishing this purpose, other objects are: 1, to actuate thevalve controlling the admission of pressure fluid by a secondary powertake-oi developing unusually great force in controlling the valveseating and other valve movements; 2, to minimize friction by employinga free pressure responsive element to actuatethe valve; and 3, to meterthe pressure fluid to the 'load'in proportion to the energy requiredmost economically to perform the work to be done.

' Either the tubing or the casing may be employed as the eduction orinduction conduit, by slightly changing the construction of the devicesemployed for flowing through oneto accomplish flow through the other.

A metallic bellows is placed in a chamber interposed between the wellliquid within an eduction tube and the pressure fluid in an inductiontube. The bellowsis secured at one end and has attached to its free enda. valve adapted to regulate and finally cut oil the flow of pressurefluid into the well liquid in the eduction tube.

The exterior of the bellows is exposed to the pressure fluid and theinterior of the bellows is exposed to the well fluid. The well liquid,9. spring interior of the bellows, and'the expansive force of thebellows, exert the valve unseating forces, and the pressure fluid exertsthe valve seating force. Each of these forces is constant, except thatof the well liquid, which varies according to location in the eductiontube. The devices are spaced at intervals in the tubing and each deviceis constructed toadmit into the educ-.

tion tube the proper volume of pressure fluid to accomplish flow fromits level by the most eflicient expenditure of pressure fluid energy.

I attain the foregoing objects by mechanism illustrated in theaccompanying drawing in which Fig. l is an installation plan of thedevices in a well, the well casing being shown in longitudinal section.

Fig. 4 shows a modified form of the device in Fig. 2 adapted for casingflow.

Fig. 5 is a cross section on the line 5-5, of

Fig. 4.

Fig. 6 is a cross section on the line 6-6, of Fig. 4. g Similarcharacters of reference are employed to designate similar partsthroughout the sevv eral views.

The differential will be understood to be the difference in pressuresobtaining within and exterior of the tubing at any level.

The column of well'liquid which stands up in the eduction conduit,responsive to pressure fluid force. will be referred to as theupstanding column.

In Flgi 2, the nipple-like body l2, which may be cast-0r otherwisefabricated integrally'with the shell or valve housing l2a, has acircular opening He in line with and of approximately the same size asthe opening through the tubing, the sloping ends 12b and l2b' of theshell being for the obvious purpose of guiding the device in .passingobstructions frequently encountered in well casing when the device ismoved longitudinally in the casing.

The bellows l9 which for example, may have a diameter of one to one andone-half inches, is mounted in the valve housing l2a. Said bellows issecured upon its upper connection H by the solder or weld Isa and issecured upon its lower end connection 2| by the solder or weld Mb. Thelower end of the bellows is closed hermetically by the packing 23, andthebushing member 22, having threaded engagement within the member 2|.The bellows may have a clearance, such as a, to 1*; inch within the wallof Fig. 2 is a longitudinal section through the preferred embodiment ofthe invention for tubing flow.

in 3 is a cross section on the line 3-4., Fig. 2.

the'bore I20. The valve tube l8 may have its lower end pressed into theupper end of the bushing 22 and further secured by the weld I 8d. Thistube has the slight annular space I between it and the central openingwithin the member I! which is mounted in the upper end of the valvechamber. The coiled spring 20, having slight clearance over the tube llandrelatively large clearance within the bellows, is installed undersome compression between its end supports l I and 22, and serves to'hold the bellowsmember resiliently extended.

The bellows I9 is secured within the bore I20 by the engagement of anannular flanged por-,

tion of the member I! upon the slightv iutemal annular should IN. Thisengagement is secured by the packing l6, urged downward by the force ofthe plug l3, having threaded engagement within the upper end of theshell Ila and transmitting 7 its force through the gland ring Ila, thepacking Ilc and another portion turned oil from the in-.

side forming another annual chamber Ila. The enlarged circular flangedportion of the member I1 is closely received within the bore in theupper portion of the shell Ila above the shoulder Ild, and the upper endof the member II has slight clearance within the central opening in theplug ll.

The check valve base ll, having the upstanding round pin 24b, hasthreaded engagement within the lower sloping end llb' of the shell Ila.The seat 24a is adapted normally to engage with the valve 22a, formedcentrally'within the lower end 01' the bushing 22. The length the pinllb, preferably, should be somewhat greater than the distance betweenthe valve Ila and the seat IIb, so that the pin will remain within themember 22 when the valve seats. The diameter of the upper end of thispin may beosuch as inch, while the base of this pin may have a diameterof V to inch. The diameter of the central opening Ilb in the tubularstem may be two to flve thousandths inch greater than the diameter ofthe pin Ila at its base.

.There is a passage from the interior of the member H to the interiorconduit Ilc' o! the eduction tube by way of opening IIa in member I'I,Ilb in the sleeve I5 and the opening It! in the tube II.

The openings I2! and 4% each may have a diameter 01' to V inch, whilethe lateral openings I'Ia may be somewhat smaller. 7

The side 01' the pin 24b may be tapered, straight, convexed, orconcaved, according to the volume of pressure fluid admitted to flow thewell at different difl'erentials.

The central circular opening within the upper portion of the member Ilmay be arcuately tapered between the lateral openings Na and theuntapered portion a. The diameter 01' the tapered opening at the lateralopenings I'Ia may be tends to decrease the flow oi pressure fluidthrough the device. The result of this contraacting relation betweenthis pin and the tapered chamber tends to admit the greatest volume ofpressure fluid through the device at the diil'er-. entialobtaining whenthe valve Ila is approxlmately midway of its travel toward the seat IIb.

If a greater volume of pressure fluid is desired to pass through thedevice at low diflerentials, the pin 24b may bemade of smaller diameter,or entirely eliminated.

The untapered portion a of the valve chamber receives'the tube ll with aclose slide valve flt.

:The valve is, therefore, a combination of slide the well fluid fromdraining back through the devices at conclusion of the flowingoperation, it being assumed that a check valve is employed in the tubingbetween the lowest device and the nipple l.

The valves Ila, Fig. 2, and ll, Fig. 4, are normally open until closedby the differential, as appears in said figures. 5 1

The path of the pressure fluid through the device shown in Fig. 2 is asfollows: out of the annular space Ia, Fig. 1, via the lateral intakeopening Ile and the annular chamber I29, surrounding the bellows, whereit unseats the valve 22a and continues consecutively through the openingIlb, the openings I'Ia, the inner annular chamber Ila, the openings Ilb,the outer annular chamber I50, and into the tubing passage Ilc', via theopening Ill.

The outside of the bellows is exposed to the pressure fluid which entersthe annular chamber Ila, surrounding the bellows, via the intake portI26. This fluid exerts the sole compression force upon the bellows andspring 20 which seats the valve Ila upon its seat I'Ib at apre-determined differential.

' The inside of the bellows is exposed to the pressure of the upstandingcolumn 01' well fluid. The

pressure of this fluid, and the force required to compress thebellowsand spring, are the only forces which urge the valve Ila away from itsseat.

The path of the valve unseating force against the inside of the bellowsis out of the tubing via the opening III, the annular space Ilc,-theopenings Ilb, the annular chamber Ila, the openings'lla, and the annularclearance Ilc.

The valve seating force remainsconstant with the value of the pressurefluid, while the valve unseatlng force varies according to the locationof the valve with relation to the upstanding column. The higher thevalve is above the base of the upstanding column. the less thisunseating' force will be, resulting in increased differentials withincreased distance from the base of the upstanding column. Thisincreasing difl'erential closes the higher valves, while the decreasingditi'erential, nearer the base of upstanding column, causes the valvesto be open there.

At the base oil this-column, these opposing forces are equal and thepressure fluid controlvalve in a device there will be wide open, as inFigs. 2 and 4. It, on'the other hand, a device is positioned in thetubing at such distance above the base of the upstanding column that theportion of fluid in that column between its base and the device exertsexactly as much force per square inch as the force required to close thevalve, then that valve will be Just closed. Higher devices will havetheir valves closed by increasing and poppet elements. Momentary highpressures in the flow tubing thus are prevented from opening the valveIla when it is seated.

force, with increasing height of their positions inthe upstandingcolumn, or above it. Each device between the one barely closed and thebase of the upstanding column will have its valve increasingly fartheraway from its seat as its position approaches the base of the upstandingv column.

the force per square inch exerted by the well liquid between adjacentdevices in order that an upper device will not close before the one nextunder it is uncovered and begins intaking prese sure fluid.

The value of the pressure fluid employed to flow the well preferablyshould be at least some two orthree times the force required to seat thevalve 88a and, of course, may be much greater. Manifestly, increasingthe value of this fluid will increase the well. I The depth from whichthe well is to be flowe the spacing of the devices, the size of theeduct-ion tube, the volume of the flow, and the physical properties ofthe well liquid, are all factors to be considered in determiningthevolume of pressure fluid to be admitted through the devices and thevalue of the pressure fluid to be employed, as those skilled in the artwill understand.

In Fig. 1, the casing and the tubing 2 have a hermetic seal formedbetween them by the casing head 4, proximately above the ground surface8. The tubing may be smaller in the lower regions of the well thanabove, the different sizes rate of liquid expulsion from the fraction ofthe pressure which would be required to expel the well liquid if it wereforced out by Y pressure fluid which could enter only through the lowerend of the tubing.

If the rate of flow from the well'be greater than the rate'of productionfrom the formation the well produces its own pressure fluid, flow byopening the unshown valve in the line 3.

being shown connected by the swaged nipple 5.

The pipe line 3 connected into the casing head may be employed to conveypressure fluid into the annular space Ia if the well does not produceenough gas to flow it or this line may be employed to convey surplus gasaway from the well.

For flowing the well through the tubing, the pipe line 6a connected intothe casing head for easing flow, will be considered as disconnected fromthe casing head and replaced by a plug.

An unshown valve in the line 3 is assumed to be closed against pressurefluid in that line of sufllcient' value to flow the well.

Expulsion of well liquid results from .the expansion of pressure fluidentering the upstanding column of well liquid in a manner well known tothe art.

The liquid level in both the tubing and the annular space to is assumedto be at A, Fig. 1.

Now, to flow the well through the tubing, open the unshown valve in theline 3, which'will quickly discharge pressure fluid into annular spacela and cause the valves in all devices above the well liquid to close.The liquid level in the annular space in will become depressed to B andthe liquid level in the tubing will rise to C. The device next to thebase of this upstanding column will be open, thi being the second devicefrom the top. The next upper device will remain closed or just opening,depending upon whether or not the unseating force of the bellows andspring, plus the weight of the upstanding column Manifestly, the flowingoperation may be repeated as often as the well will produce thenecessary liquid to provide the upstanding column.

The check valve 22a will engage its seat 21a. to prevent the tubing frombeing drained through the devices at conclusion of each flowingoperation. Unless it is desirable to reverse the pressure obcasionallyfor well-cleaning purposes, a check valve may be also employed in thetubing proximately above the nipple 6, in order to trap all suchdrainage in the tubing.

The device illustrated in Fig. 4 has a body portion "A, somewhatdiflerent from the corresponding body I! in Fig. .2, the lower end ofthe body I2A being formed into a half coupling 2a" replacing thecoupling 20 upon the; lower end of the tubing flow devices. The intakeport 29, corresponding to the opening He in Fig. 2, is moved to theinside between the bore I20 and the tubing above the upper device, isgreater or less than.

the seating force of the pressure fluid.

It is apparent that the flowing operation originates at the device nextabove the base of the upstanding liquid column and follows that columnis also apparent that the value of the pressure passage lie. 'Thedischarge port 30 in Fig. 4 corresponds in purpose to the dischargeopening I21 in Fig. 2, but is moved to the outside to dis chargepressure fluid out of the tubing 2 into the annular space to. The plug83A is slightly differently formed from the plug iii in Fig. 2, be-

cause the packing i4 employed in the latter figure is omitted from Fig.4.

The bellowsupper end connection HA is engaged upon the shoulder Rd andhas the pin base 21 engaged through its upper end. The valve seat 21a isadapted to be engagedby the valve 28 formed upon the upper end of thetube l8.

bottom'oi the bore I20. The pin base 26 has leak-proof threadedconnection within the lower sloping end i2b' and has the upstandinground tapered pin positioned centrally of the lower end of the centralopening through the tube l8.

. The pin 21?) is smallest at its lower end where it may have a diametersuch as inch. The

straight portion 12 at theupper end of this pin. may have a diametersuch as to inch. The.

pin 28a may have similar dimensions. The

length of both pins should be such that their ends will remain withinthe central opening 58b of the tube i8 in all positions thereof, as isapparent in Fig. 4.

The purpose of the upper pin 21b is to decrease fluid employed'withthese devices may be only a the bypassing space between it and the tubei8 forced open by high velocity slugs passing thedevice during theflowing operation.

If a large flow of pressure fluid through the device is desired at low,diflerentials, the lower much greater force than if the pressure fluidacted directly upon the valves.

The valves controllingv the admission of pressure fluid into theupstanding column of well liquid may be adjusted to close all at onedifferential, or they maybe adjusted to close at progressively differentdiiferentials. The volume of pressure fluid admitted through thesedevices may be also progressively varied as well as their spacing.Proper adjustment of the devices, their spacing in the well, and thevalue of the prespin 28a may be made smaller or entirely omitted.

While flowing through the casing, the path of pressure fluid through thedevice illustrated in Fig. 4 is as follows: out of the tubing space I,into the intake port 28, thence via the openings between the wings 2511,the central opening through the bushing member 25, the opening MD, theannular clearance between the members I 8 and l M, the lateral openingslla, the annular space No, the openings llib, the annular space I50,andout into the annular space la, Fig. 1, through the discharge port 88.

The valve seating force, which is exercised by the pressure fluid,enters the annular chamber I29 and surrounds the bellows via the port28.

- The pressure of the well liquid interior of the bellows, along withthe force required to compress the bellows and spring, is the valveunseating force. This force enters the bellows from the annular spacela, Fig. 1", via the discharge port 88,

the annular space I80, the openings llib, the annular space lia, and theslight annular clearance I80, between the member HA and the tube l8.

The devices may be constructed and adjusted so that the valve 28 willseal off upon the seat 21a at the same force required to seat the valvel8a upon the seat HD in Fig. 2. Likewise, the spacing of the devices inthe induction conduit 2 may -be similar to that stated for the tubingflow.

be open. The pipe line 2b is connected with pres- The well liquid isassure fluid of proper value. sumed to bestanding in both the casing andthe tubing at the common level indicated at A.

Now, to flow the well through the casing, turn 'the pressure fluid intothe tube 2 via the induction line 2b. All valves in the devices. willclose at the predetermined differential. The liquid in the tubing willquickly lower to the level indicated at D, while the liquid in theannular space in. will rise, at the same time, to the level indicated atE.

The valve in the device next above the level D will open while the valvein the device next above it will be still closed or slightly open,depending upon the differential at that level.

The action of the devices in discharging pressure fluid into theupstanding column in the annular space la to cause a well to flowthrough the casing is so similar to their action in flowing through thetubing as to be understood without further explanation.

In both forms of the invention, it will be observed that the diameter ofthe bellows is shown to be many times greater than the diameter of thevalves. It is apparent that this relation will cause the pressure fluidcontrol valves to seat with sure fluid to be employed may be variedaccording to various well conditions, as those skilled in the-art willknow.

. The invention as herein illustrated and described is manifestlysubject to many changes in construction and arrangement of parts whichwill remain within the scope and purpose of the stated objects andappended claims.

What is claimed is:

1. In a stage lift flow device for wells, a valve body including atubular housing having an opening at one end communicating with theexterior of the valve body and an opening at the other end communicatingwith the interior of the valve body, an end connecting member set in oneend of saidhousing, said member having a longitudinal recess, a bellowsdiaphragm having a sealing connection with said member whereby saiddiaphragm is supported, a tubular bushing closing the free end of saidbellows diaphragm except for an axial passage, a tubular valve stemfixed in said passage and projecting into said connecting member, avalve on one end of said stem, a seat for said valve in said member,

, meter the flow of fluid through said housing and said tubular valvestem.

2. Ina stage lift flow device for wells, a valve body including atubular housing having an opening at one end communicating with theexterior of the valve body and an opening at the other end communicatingwith the interior of the valve'body, an end connecting member set in oneend of said housing, said member having a longitudinal recess, a bellowsdiaphragm having a sealing connection with said member whereby saiddiaphragm is supported, a tubular bushing closing the free end of saidbellows diaphragm except for an axial passage, a tubular valve stemfixed in said passage and projecting into said connecting member, avalve on one end of said stem, a seat for said valve in said member,said connecting member having a lateral opening leading to one of theopenings in said housing, and a restricted passage from said one of theopenings in the housing around said valve stem to the interior of saiddiaphragm, the other opening in said housing leading to the interior ofthe housing outside said diaphragm.

3. A valve body, a tubular housing on one side thereof, said housinghavingan opening at one end to the interior of said body and an openingat the other end thereof to the outside of said .body, a bellowsdiaphragm fitting loosely in said housing, a bellows connection anchoredin the one end of said housing, said connection having an axial recesstapered to provide a valve seat and a lateral opening communicating withone of the openings in said housing, a sealing connection between saiddiaphragm and the inner end of said connection, a bushing connected withthe free end of said diaphragm, said bushing having an axial passage, atubular valve stem in said passage and projecting through said diaphragminto the recess in said connection i the interior of the body and anopening at the lower end communicating with the exterior of the body, abellows diaphragm in said ho, an anchoring connection at the upper endof said diaphra m. a bushing at the lower 'end of said diaphragm havingan axial age, a tubular valve stern anchored in said bushing andextending upwardly in said diaphragm, a valve on said stem, 9. seattherefor in said connection,

a fluid passage from the interior of said did-- phragrn to said upperopening, the outer surface of said diaphragm being exposed to fluidpressure through said lower opening, and means at the 7 lower end ofsaid housing to close the passage of fluid through said valve stem whensaid valve is open to its greatest extent.

5. A valve body, a housing thereon having an I opening at the upper endthereof connected with the interior of the body and an'opening at thelower end counicating with the exterior of the body, a bellows diaphragmin said housing,

an anchoring connection at the upper end of said diaphragm, a bushing atthe lowerend of said diaphragm having an axial passage, a tubular valvestem anchored inid bushing and extending upwardly in said diaphragm, avalve on said stem, a seat therefor in said connection. a fluid pee fromthe interior of said diato said upper opening, the outer surface of saiddiaphragm. being exposed to fluid pressure through said lower opening,and mns at each end of said tubular stem to meter the fluid passingthrough said stem during the movement of said valve in response to fluidpressure upon said diaphra.

s i3 XAND BOYNTON.

